django forms: editing multiple sets of related objects in a single form

Question

I\'m trying to do something that should be very common: add/edit a bunch of related models in a single form. For example:

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Answer 1

So, as you've seen, one of the things about inlineformset_factory is that it expects two models - a parent, and child, which has a foreign key relationship to the parent. How do you pass extra data on the fly to the form, for extra data in the intermediary model?

How I do this is by using curry:

from django.utils.functional import curry

from my_app.models import ParentModel, ChildModel, SomeOtherModel

def some_view(request, child_id, extra_object_id):
    instance = ChildModel.objects.get(pk=child_id)
    some_extra_model = SomeOtherModel.objects.get(pk=extra_object_id)

    MyFormset = inlineformset_factory(ParentModel, ChildModel, form=ChildModelForm)

    #This is where the object "some_extra_model" gets passed to each form via the
    #static method
    MyFormset.form = staticmethod(curry(ChildModelForm,
        some_extra_model=some_extra_model))

    formset = MyFormset(request.POST or None, request.FILES or None,
        queryset=SomeObject.objects.filter(something=something), instance=instance)

The form class "ChildModelForm" would need to have an init override that adds the "some_extra_model" object from the arguments:

def ChildModelForm(forms.ModelForm):
    class Meta:
        model = ChildModel

    def __init__(self, some_extra_model, *args, **kwargs):
        super(ChildModelForm, self).__init__(*args, **kwargs)
        #do something with "some_extra_model" here

Hope that helps get you on the right track.